Another benefit that the NII model provides over the 645N model is that it has a custom setting that will allow 16 frames/roll(120) or 32/roll(220). That for me was another reason to go with the 645NII model, despite the price difference...
Film isn't getting cheaper, nor is PROFESSIONAL development by a good lab. Getting more frames/roll saves me money in the long run... Especially when shooting 220 film, its like using a BIG 35mm camera

Dan